The iontophoresis is a system used for quickening skin absorption with electricity. The object of the iontophoresis is to quicken permeation of medicine molecules through the skin barrier with good use of a force that moves positively charged molecules from positive pole to negative pole and negatively charged molecules from negative pole to positive pole in an electric field generated mainly due to current conducting. [Refer to (Journal of Controlled Release) pp. 213 to 220, Vol. 18, 1992; Advanced Drug Delivery Review) p. 119, Vol. 9, 1992; Pharmaceutical Research) pp. 318 to 326, Vol. 3, 1986.]
Such an iontophoresis device having been known well is provided with means for checking whether or not the movement of molecules (including drugs) is done normally. The checking means in this case may be, for example, a method for measuring an output current with respect to a voltage output from an applied DC. According to this method, a conducting or non-conducting state is checked by applying a comparatively high voltage to the object spot at the beginning of energization. When the output current is in a predetermined value or less, it is decided as abnormal, thereby the voltage output stops.
The official gazette of National Publication of International Patent Application No. 10-510179 discloses a power-driven transportation unit used to monitor both current and voltage of the power-driven transportation. This transportation unit, when the impedance on the object human skin is stabilized for a predetermined time after the device is started up, begins monitoring of both current and voltage of the transportation. When the monitored value is not within a predetermined value, the output stops.
In case of the above described method that makes the monitoring by applying a comparatively high voltage to the object spot at the beginning of energization, however, a problem arises; concretely, the high output voltage makes the user feel malaise. In addition, the above described method which begins monitoring of both current and voltage of the power-driven transportation after the impedance on the object spot skin is stabilized is to be confronted with another problem that the current conducting state cannot be confirmed until the impedance on the object spot skin is stabilized.
Under such circumstances, it is an object of the present invention to solve the above conventional problems and provide an iontophoresis device preferred to detect abnormal conductivity at the beginning of energization and during energization.